At least six suspects have been arrested in southeastern Turkey in a case related to a child's kidnapping by the PKK terror group, a security source said on Thursday.

Five years ago, a teenager was kidnapped by the terror group and forced to join their ranks. He recently surrendered to Turkish forces, said the source, who asked not to be named due to restrictions on speaking to the media.

Prosecutors in the southeastern Diyarbakir province launched an investigation into the network which plotted the kidnapping, said the source.

Based on the confessions of the surrendered terrorist, addresses of the suspects were raided and another suspect was held.

The operation continues to capture a fugitive suspect, identified only by the initials T.D.

In Turkey, offenders who are linked to terrorist groups and surrender are eligible for possible sentence reductions under a repentance law.

In its more than 30-year terror campaign against Turkey, the PKK -- listed as a terrorist organization by Turkey, the US, and the EU -- has been responsible for the deaths of some 40,000 people, including women, children, and infants.